IMPROVEMENTS IN THE MINING OF COAL OR THE LIKE

摘要

1,272,253. Mineral-mining process. HENKEL & CIE G.m.b.H. 30 Sept., 1969 [24 Feb., 1969], No. 47912/69. Heading E1F. [Also in Divisions C3 and F3] A shock impregnation process, i.e. a process for facilitating the mining or loosening of the coal or mineral whereby one or severalholes are bored into the coal seam &c. and water under high pressure is forced into these relatively small holes, in which the impregnating solution is an aqueous solution having a content of from 0.1 to 10% by weight of polyvinyl alcohol referred to water, and from 1 to 50% by weight, based on the amount of polyvinyl alcohol, of a borate, the solution having a pH value of over 7 up to 12 and a gel-like form. The preferred borate is borax.